WireBox: The Enterprise Dependency Injection Framework

Covers up to version 1.7

Introduction

WireBox is an enterprise ColdFusion dependency injection and AOP framework. This project has been part of ColdBox since its early version 2.0 releases but it is also a standalone library that can be used in ANY ColdFusion application or framework. WireBox's inspiration has been based on the idea of rapid workflows when building object oriented ColdFusion applications, programmatic configurations and simplicity. With that motivation we introduced dependency injection by annotations and conventions, which has been the core foundation of WireBox. We have definitely been influenced by great DI projects like Google Guice, Grails Framework, Spring and ColdSpring so we thank them for their contributions and inspiration.

Overview

Dependency injection is the art of making work come home to you.
- Dhanji R. Prasanna

WireBox alleviates the need for custom object factories or manual object creation in your ColdFusion applications. It provides a standardized approach to object construction and assembling that will make your code easier to adapt to changes, easier to test, mock and extend.

As software developers we are always challenged with maintenance and one ever occurring annoyance,change. Therefore, the more sustainable and maintainable our software, the more we can concentrate on real problems and make our lives more productive. WireBox leverages an array of metadata annotations to make your object assembling, storage and creation easy as pie! We have leveraged the power of event driven architecture via object listeners or interceptors so you can extend not only WireBox but the way objects are analyzed, created, wired and much more. To the extent that ourAOP capabilities are all driven by our AOP listener which decouples itself from WireBox code and makes it extremely flexible.

We have also seen the value of a central location for object configuration and behavior so we created our very own WireBox Programmatic Mapping DSL (Domain Specific Language) that you can use to define object construction, relationships, AOP, etc in pure ColdFusion (No XML!). We welcome you to stick around and read our documentation so you can see the true value of WireBox in your web applications.

Fact : WireBox has been running and powering mission critical ColdFusion applications since 2009 and now you can too.

Installing WireBox

WireBox can be downloaded as a separate framework or it is included with the latest ColdBox Platform release. The main difference between both versions is the instantiation and usage namespace, the rest is the same.

Standalone

wirebox.system.ioc

ColdBox

coldbox.system.ioc

Download

System Requirements

ColdFusion 8 and above

Railo 3.1 and above

Installation

If you are using WireBox within a ColdBox application context, then WireBox is part of the platform. Just install ColdBox normally. If you are using WireBox standalone, just drop WireBox in your application root or create a mapping called wirebox that points to the installation folder. If you can run the following snippet, then WireBox is installed correctly:

Note: Please remember that if you use the standalone version the namespace is wirebox.system.ioc and if you use the ColdBox application version it is coldbox.system.ioc. From this point on, we will use the standalone namespace for simplicity.

Advantages of a DI Framework

Compared to manual DI, using WireBox can lead to the following advantages:

You will write less boilerplate code.

By giving WireBox DI responsibilities, you will stop creating objects manually or using custom object factories.

You can leverage object persistence scopes for performance and scalability. Even create time persisted objects.

You will not have any object creation or wiring code in your application, but have it abstracted via WireBox. Which will lead to more cohesive code that is not plagued with boilerplate code or factory code.

Objects will become more testable and easier to mock, which in turn can accelerate your development by using a TDD (Test Driven Development) approach.

Once WireBox leverages your objects you can take advantage of AOP or other event life cycle processes to really get funky with OO.

Getting Jiggy Wit It!

A primer to WireBox usage

Dependency injection and instance construction with WireBox is easy. In its most simplest form we can just leverage annotations and be off to dancing Big Willy style! You can use our global injection annotation inject on cfproperties, setter methods or constructor arguments. This annotation tells WireBox to inject something in place of the property, argument or method; basically it is your code shouting "Hey buddy, I need your help here". What it injects depends on the contents of this annotation that leverages our injection DSL (Domain Specific Language). The simplest form of the DSL is to just tell WireBox what mapping to bring in for injection. Please note that I say mapping and not object directly, because WireBox works on the concept of an object mapping. This mapping in all reality can be a CFC, a java object, an RSS feed, a webservice, a constant value or pretty much anything you like. If you don't like annotations because you feel they are too intrusive to your taste, don't worry, we also have a programmatic configuration binder you can use to define all your objects and their dependencies. We will discuss object mappings and our configuration binders later on, so let's look at how cool this is by checking out our Coffee Shop sample class. The CoffeeShop class below will use our three types of injections to showcase how WireBox works, please note that most likely we would build this class by picking one or the other, which in itself brings in pros and cons for each approach.

So let's break this class down. First, you can see a singleton annotation on the component declaration. This tells WireBox that this class should only be created once and then cached in its internal singleton scope of the injector. In other words, this is called object life scopes. You can refer to the persistence scopes annotations later on in the guide to learn all about how to scope your classes.

Second, we built our coffee shop class with three external dependencies: 1 by cfproperty, 1 by constructor argument and 1 by setter injection. Again, you can see later on in this guide the difference between all these injection styles and choose what you prefer. In this example, we just showcase the different injection styles. Also, as you can see from the source code the three types of injection uses the inject annotation but with different content:

If you just mark a property, argument or method with the inject annotation, WireBox will assume it is a mapping and the ID should be either the property name, the argument name or the method name. However, if you want to specify the id in the DSL string, just use the simple id:{mapping} dsl notation. That's it! Isn't that cool, you just mark out your dependencies and WireBox will build and inject them for you!

The method has a cool little annotation called onDIComplete that tells WireBox that after all DI dependencies have been injected, then execute the method. That is so cool, WireBox can even open the coffee shop for me so I can get my espresso fix. Not only that but you can have multiple onDIComplete methods declared and WireBox will call them for you (in discovered order). These are called object post processors that are discovered by annotations or can be configured via our configuration binder and we will learn about them later on. WireBox also fires a series of object life cycle events throughout an object's life span in which you can build listens to and actually perform some cool stuff on them. So now that we got all excited about opening the coffee shop let's get into something even more interesting, unit testing and mocking.

Another important aspect leveraging DI concepts when building our components is that we can immediately write tests for them and leverage mocking to test for actual behaviors. This is a great advantage as it allows you to rapidly test to confirm your component is working without worrying about building or assembling objects in your tests. You have eliminated all kinds of crazy creation and assembler code and just concentrated yourself on the problem at hand. You are now focused to code the greatest piece of software you have ever imagined, thanks to WireBox!

So let's build our unit test (Please note we use our base ColdBox testing classes for ease of use and MockBox integration):

Now we can run our tests and verify that our coffee shop is operational and producing sweet sweet espresso!

Instance Creations

We have now coded our classes and unit tests with some cool annotations in record time, so what do we do next? Well, WireBox works on the idea of three ways to discover and create your classes:

Approach

Motivation

Pros

Cons

Implicit Mappings

To replace createObject() calls

Very natural as you just request an object by its instantiation path. Very fast prototyping.

Refactoring is very hard as code is plagued with instantiation paths everywhere. Not DRY.

Explicit Mappings

To replace createObject() calls with named keys

DRY, you can create multiple named mappings that point to the same blueprint of a class. Create multiple iterations of the same class. Very nice decoupling.

Not as fast to prototype as we need to define our mappings before hand in our configuration binder.

Scan Locations

CFC discovery by conventions

A partial instantiation path(s) or folder(s) are mapped so you can retrieve by shorthand names. Very quick to prototype also without using full instantiation paths. Override of implementations can be easily done by discovery.

Harder concept to digest, not as straightforward as implicit and explicit locations.

So let's do examples for each where our classes we just built are placed in a directory called model of the root directory.

So our recommendation is to always try to create configuration binders as best practice, but your requirements might dictate something else.

Binder Introduction

In all reality we could be building our objects and its dependencies, object graph, without any configuration just plain location and implicit conventions. This is great but not very flexible for refactoring, so let's do the best practice of defining a mapping or an alias to a real object. We do this by creating a WireBox configuration binder (wirebox.system.ioc.config.Binder), which is a simple CFC that defines the way WireBox behaves and defines object mappings. This binder is then used to initialize WireBox so it has knowledge of these mappings and our settings.

Note: Building object graphs manually is tedious, error prone and makes testing very difficult. That is what Inversion of Control is all about, you will surrender creation and wiring control to somebody else. Come on! Don't hold on! Release! Say it with me: Release!

component extends="coldbox.system.ioc.config.Binder"{
public configure(){
// Map the espresso machine
map("espressoMachine")
.to("model.EspressoMachine")
.asSingleton();
// or in a more short manner, map a path and the id becomes the name of the CFC
mapPath("model.EspressoMachine").asSingleton();
// map the coffee shop if you want, remember we can wire by conventions also
mapPath("model.CoffeeShop").asSingleton();
// map the owner
mapPath("model.Owner").asSingleton();
}
}

Important: All objects in WireBox are considered to exist in the No Scope or are transient objects. You must specifically tell WireBox in what scope to persist objects like singletons, time persisted, etc.

Easy enough? We use the object map binding DSL that tells WireBox how to map objects. You can also read it from left to right and it will make sense: "map EspressoMachine to the model.EspressoMachine CFC and treat it as a singleton. How cool is that! The last part is putting it together:

Again, we recommend you create mappings for your objects as it decouples them from their exact instantiation locations, which WireBox should only know about. This makes refactoring much easier and you can name your objects as you please as you only refer to them via aliases. Please note that WireBox helps eliminate all this creation and wiring boilerplate code and makes our software much more maintainable and testable than before. We can very easily change object implementations and change behavior without any coding at all. We are always in search of the holy grail of OO, decoupling and cohesion; hopefully WireBox can take you a little closer to perfection. So now that you have seen a little about WireBox, let's get our feet wet and start dancing Willy style!

Scoping

We touched briefly on singleton and no scope objects in this section, so let's delve a little into what scoping is. WireBox's default behavior is to create a new instance of an object each time you request it via creation or injection (Transient/Prototype objects), this is the NO SCOPE scope. Scopes allow you to customize the object's life span and duration. The singleton scope allows for the creation of only one instance of an object that will live for the entire life span of the injector. WireBox ships with several different life span scopes but you can also create your own custom scopes (please see the custom scopes section). You can also tell WireBox in what scope to place the instance into by annotations or via the configuration binder. We have an entire section dedicated to discovering all the WireBox annotations, but let's get a sneak peek at them and also how to do it via our mapping DSL.

Scope Annotations

You can tag a cfcomponent tag or component declaration with a scope={named scope} annotation that tells WireBox what scope to use

You can have nothing on the cfcomponent tag or component declaration which denotes the NO SCOPE

You can tag a cfcomponent tag or component declaration with a singleton annotation

This is cool! We can now have full control of how objects are persisted via the WireBox injector, we are not constricted to one type of persistence anymore.

Important : If you use a persistence scope that expires after time like session, request, cachebox, etc, you will experience a side effect called scope widening injection. WireBox offers a solution to this side effect via WireBox Providers, which we will cover in detail.

Eager Init

Another aspect of our objects is when are they created? Good question! By default all objects are created ONLY when they are requested, in other words they are lazy created. But what if you are spoiled and you want your stuff NOW NOW NOW! Well, you can, you rude little brat! Just tell WireBox that you want your objects to be eagerly created. How? Via the mapping DSL and our cool asEagerInit() function.

How WireBox Resolves Dependencies

Most of the time we believe our DI engines should be black boxes, but we try to think otherwise. We encourage developers to know what is going on so they can debug easily and not hit their foreheads against their keyboards. Believe me, I have done so before. That is why WireBox is tightly integrated with LogBox to provide incredible debugging information to ANY appender you desire so you can know what is going on. Another aspect of knowing what the DI engine does is how dependencies are resolved. Here is a typical flow of injection:

Instance Creation

Object is requested by name and the Injector tries to check if the mapping exists for that name. If no mapping is found then it tries to locate the object by using the internal scan locations to try to find it. If it cannot find it and there is a parent injector defined, then the request is funneled to the parent injector and we start our process again. If no parent injector is declared and no localization, then we throw a not located exception.

If the object was found via the scan locations, then we register a new mapping according to its location and discover all the metadata out of the object in preparation for construction and DI

We now have a guaranteed mapping so we retrieve it and we verify if the mapping's metadata has been processed or not. If the mapping is marked with no autowiring then we skip to the next step. If not, we process the mapping's metadata and prepare it for DI

We verify that the scope define for the mapping exists, else we throw an invalid scope exception

We ask the scope to produce the mapping object for us. The scope is in charge of persistence, locking, etc.

The scope builds the instance by asking the injector to build a new instance with the correct constructor and constructor arguments and stores it in its scope once the injector builds it. The builder decides what type of construction is needed for the mapping as it can be a CFC, java object, webservice, RSS feed, factory method call, etc. Each constructor argument is processed for dependency resolution.

The scope then sends the instance for DI wiring and process back to the injector

The injector returns the instance

Dependency Resolution

Arrive at the desired injection point and get the injection DSL. If the DSL is empty, then it defaults to the id/model namespace. For this injection DSL Namespace we try to find a valid DSL builder for it. If none is found an exception is thrown. If we have a match, then the DSL builder is called with the DSL string to retrieve.

The DSL builder then tries to parse and process the DSL string for object retrieval. If the DSL is a WireBox mapping then we try to retrieve the instance by name (Refer back to Instance Creation).

If the builder could not produce an instance, it is logged and DI is skipped on it.

Important: Circular dependencies are supported in all injection styles within WireBox. With one caveat, if you choose constructor arguments with circular dependencies, you must use object providers.

The WireBox Injector

WireBox bases itself on the idea of creating object injectors (wirebox.system.ioc.Injector) that in turn will produce and wire all your objects. You can create as many injector instances as you like in your applications, each with configurable differences or be linked hierarchically by setting each other as parent injectors. Each injector can be configured with a configuration binder or none at all. If you are a purely annotations based kind of developer and don't mind requesting pathed components by convention, then you can use the no-configuration approach and not even have a single configuration file, all using autowiring and discovery of conventions. However, if you would like to alter the behavior of the injector and also create object mappings, you will need a configuration binder. The next section explains the way to create this configuration binder, below is how to startup or bootstrap the injector in different manners:

The WireBox injector class is the pivotal class that orchestrates DI, instance events and so much more. We really encourage you to study its API Docs to learn more about its construction and usage methods.

Injector Constructor Arguments

The injector can be constructed with three optional arguments:

Argument

Type

Required

Default

Description

binder

instance or instantiation path

false

wirebox.system.ioc.config.DefaultBinder

The binder instance or instantiation path to be used to configure this WireBox injector with

properties

struct

false

structnew()

A structure of name value pairs usually used for configuration data that will be passed to the binder for usage in configuration.

coldbox

coldbox.system.web.Controller

false

null

A reference to the ColdBox application context you will be linking the Injector to.

If you are using WireBox within a ColdBox application, you don't even need to do any of this, we do it for you by using some configuration data in your ColdBox configuration file or conventions. Please see the ColdBox application section for more information.

Injection Idioms

Now that we have constructed our injector let's discuss a little about injection idioms or styles WireBox offers before we go all cowboy and start configuring and using this puppy. Below is a nice chart that showcases the WireBox injection styles, but we really encourage you to review our dependency injection section to learn the different approaches to DI, their values, and when to use them.

Injection Location

Injection Order

Motivation

Comments

Constructor

First

Mandatory dependencies for object creation

Each constructor argument receives a inject annotation with its required injection DSL. Be careful when dealing with object circular dependencies as they will fail via constructor injection due to its chicken and the egg nature.

CFProperty

Second

Great documentable approach to variable mixins to reduce getter/setter verbosity

Leverages the greatest aspect of ColdFusion, dynamic language, to mixin variables at runtime by using the cfproperty annotations. Great for documentation and visualizing object dependencies and safe for circular dependencies. Cons is that you can not use the dependencies in an object's constructor method.

Setter Methods

Third

Legacy classes

The inject annotation MUST exist on the setter method if the object is not mapped. Mapping must be done if you do not have access to the source or you do not want to touch the source.

These are the three injection styles that WireBox supports and which style you choose depends on your requirements and also your personal taste. The setter method approach is linked to the way Spring and ColdSpring approach it which is the traditional JavaBean style of setXXX where XXX is the name of the mapping or object to pass into the setter method for injection.

Note: Whichever injection style you use with WireBox, the target's visibility does not matter. This means that you can create private or package methods and WireBox will still inject them for you. This is absolutely great when you are an encapsulation freak and you do not want to expose public setter methods.

Common Methods

The following chart shows you the most common methods when dealing with the WireBox Injector. This doesn't mean there are no other methods on the Injector that are of value, so please check out the CFC Docs for more in-depth knowledge.

Method Signature

Comments

autowire(target,[mapping],[targetID],[annotationCheck])

A method you can use to send objects to get autowired by convention or mapping lookups

clearSingletons()

A utility method that clears all the singletons from the singleton persistence scope. Great to do in development.

containsInstance(name)

Checks if an instance can be created by this Injector or not

getBinder()

Get the configuration binder for this injector

getInstance([name],[dsl],[initArguments])

The main method that asks the injector for an object instance by name or by autowire DSL string.

getObjectPopulator()

Retrieve the ColdBox object populator that can populate objects from JSON, XML, structures and much more.

getParent()

Get a reference to the parent injector (if any)

getScope(name)

Get a reference to a registered persistence scope

setParent(injector)

Set a parent injector into the target injector to create hierarchies

Configuring WireBox

You can configure WireBox in two approaches:

1. Create a simple configuration CFC that has a configure(binder) method that accepts a WireBox configuration binder object

component{
function configure(required binder){
}
}

2. Create a configuration CFC that extends the WireBox configuration object: coldbox.system.ioc.config.Binder and has a configure() method.

The latter approach will be less verbose when talking to the mapping DSL the Binder object exposes. However, both are fully functional and matter of preference.

From the configure() method you will be able to interact with the Binder methods or creating implicit DSL structures in order to configure WireBox for operation and also to create object mappings.

Please also note that the Binder itself has a reference to the current Injector it belongs to (getInjector()).

Binder Configuration Properties

Whether you use WireBox standalone or within a ColdBox context a Binder gets a structure of configuration properties so it can use them whenever you are configuring it or declaring mappings. If you are in standalone mode, the Injector can be constructed with a properties structure that will be passed to the binder for usage. If you are in a ColdBox application the ColdBox application configuration structure is passed for you. You can then use these properties with the following methods:

getProperty(name,[default]) : Get a specific property

getProperties() : Get all the properties structure

propertyExists(name) : Check if a property exists

setProperty(name,value) : Dynamically add properties to the structure

ColdBox Enhanced Binder

If you are using your configuration binder within a ColdBox application you will have some extra goodies in the Binder that come in very handy:

getColdBox() : Retrieve the instance of the running ColdBox application

getAppMapping() : Get the current AppMapping setting for the running ColdBox application

// map the model folder
mapDirectory( getAppMapping() & ".model" );

Types & Scopes

Each configuration binder has two public properties accessible in the this scope:

this.TYPES : A reference to coldbox.system.ioc.Types used to declare what type of object you are registering for construction or wiring

this.SCOPES : A reference to coldbox.system.ioc.Scopes used to declare in what life cycle scope the object will be stored under

These two classes contain static public members in the this scope that facilitate the declaration of persistence scopes and construction types for object mappings. Below are the valid enumerations for these two classes:

this.TYPES.

CFC : Construction of a CFC

JAVA : Construction of a Java class

WEBSERVICE : Construction of a webservice object

RSS : Construction of an RSS feed

DSL : Construction by DSL string

CONSTANT : A constant value

FACTORY : Construction by factory method

this.SCOPES.

NOSCOPE : Transient objects

PROTOTYPE : Transient objects

SINGLETON : Objects constructed only once and stored in the injector

SESSION : ColdFusion session scoped based objects

APPLICATION : ColdFusion application scope based objects

REQUEST : ColdFusion request scope based objects

SERVER : ColdFusion server scope based objects

CACHEBOX : CacheBox scoped objects

Implicit Configuration Settings

In this configure() method you can create a structure called wirebox in the variables scope that will hold the configuration data for WireBox. The following are the keys you can create in this structure:

Key

Type

Required

Default

Description

logBoxConfig

instantiation or xml path

false

coldbox.system.ioc.config.LogBox

The LogBox configuration to use when logging. If you are within a ColdBox application context, this value is ignored.

cacheBox

struct

false

{enabled=false}

A structure that defines the tight integration between WireBox and CacheBox (explained below). If you are within a ColdBox application context, this value is ignored.

scopeRegistration

struct

false

{enabled=true,scope="application",key="wirebox"}

A structure that tells WireBox to register itself into ANY ColdFusion scope once instantiated. By default, each injector get's loaded into application scope with a key of wireBox, which we encourage you to modify.

customDSL

struct

false

{}

A structure where you will register your own DSL Namespace implementations. Please refer to our Custom DSL section.

customScopes

struct

false

{}

A structure where you will register your own object scope implementations. Please refer to our Custom Scopes section.

scanLocations

array

false

[]

An array of instantiation locations WireBox will use (in order) when searching for objects when they are requested by convention.

stopRecursions

array

false

[]

An array of class paths that WireBox will detect when inspecting objects for dependencies and STOP the inspection when doing inheritance recursion.

parentInjector

object

false

---

The actual instance to a parent injector you would like to configure this injector with.

listeners

array of structs

false

---

A array of listener definitions that will be registered with this injector and listen to object life cycle events.

Please note that it is completely optional to use the implicit structure configuration. You can use the programmatic methods instead. Each configuration key has the same method in the binder for programmatic configuration.

logBoxConfig

A string containing the path of the LogBox configuration file. If you are using WireBox within a ColdBox application this setting is ignored.

wirebox.logBoxConfig = "coldbox.system.ioc.config.LogBox";

cachebox

If you are using WireBox within a ColdBox application this setting is ignored. The following are the keys for this configuration structure:

scanLocations

The instantiation paths that this Injector will have registered to do object locations in order. So if you request an object called Service and no mapping has been configured for it, then WireBox will search all these scan locations for a Service.cfc in the specified order. The last lookup is the no namespace lookup which basically represents a createObject("component","Service") call. If you are using WireBox within a ColdBox application, ColdBox will register the models convention folder for you and also whenever a ColdBox module is activated, that module's model convention folder will be added here too.

Important: Please note that order of declaration is the same as order of lookup, so it really matters. Also note that this setting only makes sense if you do not like to create mappings for objects and you just want WireBox to discover them for you.

wirebox.scanLocations = ["model","transfer.com","org.majano"];

stopRecursions

This is an array of class path's that WireBox will use to stop recursion on any object graph that has inheritance when looking for dependencies. For example, let's say your object inherits from transfer.com.TransferDecorator, but you don't want WireBox to go past that inheritance class when looking for DI data, then you would add transfer.com.TransferDecorator to this setting.

listeners

This section only shows you how to register WireBox listeners, so please refer to the object life cycle events section for more information. This setting is an array of listener structure definitions that WireBox's event manager will use when broadcasting object life cycle events. Each interceptor structure definition has the following keys:

Key

Type

Required

Default

Description

class

class path

true

---

The instantiation class path of the listener

name

string

false

Name of the CFC

The unique name of this listener when registered in our event manager. We recommend setting one up as best practice, else the name of the CFC file will be used instead. This setting is great for registering the same class with different configurations.

properties

struct

false

{}

A structure of configuration data for this listener

Important: Please note that order of declaration is the same as order of execution, so it really matters, just like ColdBox Interceptors. Please note that if you are using WireBox within a ColdBox application, you can also register listeners as interceptors in your ColdBox configuration file.

Mapping DSL

WireBox can also be configured by using the programmatic Mapping DSL exposed in the configuration binder instead of the implicit data structures DSL we just saw. Our recommendation is to use this mapping DSL as it makes your configuration become alive and more human readable than creating a bunch of arrays and structures. All mappings DSL methods return back an instance of the binder so you can concatenate methods to create readable execution chains:

map("Lui")
.to("model.Awesomeness")
.asEagerInit()
.asSingleton();

WireBox Configuration

The configuration binder has the same methods as the implicit structures that can be used to configure WireBox for operation:

Method Signature

Description

cacheBox([configFile],[cacheFactory],[enabled],[classNamespace])

The method used to configure the injector's CacheBox integration. Ignored in an application context

listener(class,[properties],[name])

The method used to register a new listener within the injector's event manager.

logBoxConfig(config)

The method used to tell the injector which LogBox configuration file to use for logging operations. Ignored in an application context

mapDSL(namespace,path)

The method used to register a new DSL annotation namespace with a DSL Builder object.

mapScope(annotation,path)

The method used to register a new custom scope in this injector.

parentInjector(injector)

Register a CFC reference to be the parent injector for the configuring injector

removeScanLocations(locations)

A method used to remove one or a list (array) of scan locations from the configuration binder

reset()

Reset the entire configuration binder to factory defaults

scanLocations(locations)

A method used to add one or a list (array) of scan locations to the configuration binder. If a path already exists it will not be appended again.

scopeRegistration(enabled,scope,key)

This method is used to tell the Injector if it should auto-register itself in any ColdFusion scope automatically.

stopRecursions(classes)

A method used to register one or a list (array) of class paths the injector will look out for when discovering DI metadata. If these classes are found in the inheritance chain of an object, the injector will not process that inherited chain.

Mapping Initiators

Ok, now that we know how to configure WireBox, let's get into the fun stuff of object mapping. How do we do this? By using our DSL mapping initiators that tell WireBox how to start the object registration process. You will then concatenate the initiators with some DSL destinations methods, DI data, etc to tell WireBox all the information it might need to construct, wire and persist the object. Here are the DSL initiators:

Method Signature

Description

map(alias)

The method that starts the mapping process. You pass in a mapping name or a list of names to start registering.

mapPath(path)

Map a CFC instantiation path. This method internally delivers a two-fold punch of doing map('CFCFileName').to(path). This is a quick way to map a CFC instantiation path that uses the name of the CFC as the mapping name.

mapDirectory(packagePath,[include],[exclude], [influence], [filter])

A cool method that tells WireBox to automatically register ALL the CFCs found recursively in that instantiation package path. All CFCs will be registered using their CFC names as the mapping names and WireBox will inspect all the CFCs immediately for DI metadata. The include and exclude arguments can be used for inclusions/exclusions lists via regex. The influence argument can be a UDF or closure that will affect the iterating registrations of objects. The filter argument can be a UDF or closure that will filter out or in the CFCs found, an include/exclude on steroids.

unMap(alias)

Unmap/delete a mapping in the binder.

with(alias)

This method is a utility method that retrieves the alias mapping so you can start concatenating methods for that specific mapping. Basically putting it into a workable context.

Important: From the methods we have seen above only the map() and with() methods require a DSL destination.

MapDirectory() Influence & Filters

The mapDirectory() allows you to leverage closures or UDF'sto influence and filter mappings. The arguments are filter to add a filter that MUST return boolean in order to process the mapping and influence that can influence the created mapping with any custom bindings.

Mapping Destinations

The mapping destinations tell WireBox what type of object you are mapping to. You will usually use these methods by concatenating map() or with() initiator calls:

Method Signature

Description

to(path)

Maps a name to a CFC instantiation path

toDSL(dsl)

Maps a name to DSL builder string. Construction is done by using this DSL string (Look at Injection DSL)

toFactoryMethod(factory,method)

Maps a name to another mapping (factory) and its method call. If you would like to pass in parameters to this factory method call you will use the methodArg() DSL method concatenated to this method call.

toJava(path)

Maps a name to a Java class that can be instantiated via createObject("java")

toProvider(provider)

Maps a name to another mapping (provider) that must implement the WireBox Provider interface (coldbox.system.ioc.IProvider)

toRSS(path)

Maps a name to an atom or RSS URL. WireBox will then use the cffeed tag to construct this RSS feed. It builds out into a structure with two keys:

metadata : The metadata of the feed

items : The items in the feed

toValue(value)

Maps a name to a constant value, which can be ANYTHING.

toWebservice(path)

Maps a name to a webservice WSDL URL. WireBox will create the webservice via createObject("webservice") for you.

Important : Please note that WireBox can create different types of objects for DI. However, only CFCs will be inspected for autowiring automatically unless you specifically tell WireBox that a certain mapping should not be autowired. In this case you will use the dependencies DSL to define all DI relationships.

Persistence DSL

The next step in our mapping DSL excursion is to learn about how WireBox will persist these object mappings into WireBox scopes. By default (as we have seen), all object mappings are transient objects and they belong to a scope type called NOSCOPE. However, we need to specifically tell WireBox into what scope the declared mapped objects should be placed on in order for us to leverage caching, the singleton pattern, etc. This is accomplished by leveraging our persistence component annotations or the following methods if you prefer a non-annotation approach:

Note: Please note that all WireBox configuration binders have two public properties:

this.TYPES - Enum class (coldbox.system.ioc.Types)

this.SCOPES - Enum class (coldbox.system.ioc.Scopes)

These classes have on themselves several public properties that are a cool shorthand way to link to construction types or persistence scopes.

Method Signature

Description

asSingleton()

Maps an object to the WireBox internal Singleton scope

into(scope)

Maps an object to a valid WireBox internal scope or any custom registered scopes by using the registered scope name. Valid internal WireBox scopes are:

Important : Please note that by leveraging scopes that can expire such as cachebox,request,session,applications,etc you must take into account the way they are injected into other objects. They can experience a DI side effect called scope widening injection that can link an object reference that expires into another object reference that does not expire (like singleton). This causes nasty side effects and issues, so please refer to the WireBox Providers section to find out how you can avoid this nasty pitfall by using WireBox providers.

Dependencies DSL

The dependencies DSL methods are mostly used to define dependencies and also to activate advanced features on target objects, such as runtime mixins, virtual inheritance, etc.

Please note that you can concatenate more than one of these methods calls to dictate multiple constructor arguments, setter methods, cf properties, and more.

Method Signature

Description

constructor(constructor)

Tells WireBox which constructor to call on the mapped object. By default if an object has an init() method, that will be used as the constructor

noInit()

Tells WireBox that this mapped object will skip the constructor call for it. By default WireBox always calls object constructors

threadSafe()

Tells WireBox that the mapped object should be constructed and then wired with a strict concurrency lock for property injections, setter injections and onDIComplete(). Please be aware that if you use this mode of construction, circular dependencies are not allowed. The default is that property and setter injections and onDIComplete() are outside of the construction locks.

notThreadSafe()

Tells WireBox to construct objects by locking only the constructor and constructor argument dependencies to allow for circular dependencies. This is the default construction mode of all persisted objects: singleton, session, server, application and cachebox scope.

noAutowire()

Tells WireBox that this mapped object has its dependencies described programmatically instead of using metadata inspection to discover them.

parent(alias)

Tells WireBox that this mapped object has a parent mapping with definitions it should use to base it from. This feature provides a great way to reuse object mapping definitions.

initArg([name],[ref],[dsl],[value],[javaCast])

Used to define a constructor argument for the mapped object.

name : The name of the constructor argument. Not used for Java or Webservice construction

dsl : The construction dsl that will be used to construct this constructor argument

value : The constant value you can use instead of a dsl or ref for this constructor argument

javaCast : If using a java object, you can cast the value of this constructor argument

initWith()

You can pass as many arguments (named or positional) to this method to simulate the init() call of the mapped object. WireBox will then use that argument collection to initialize the mapped object. Note, initWith() only accepts arguments which can be evaluated at the time the binder is parsed such as static values, or binder properties. To specify mapping IDs or DSLs, use initArg().

methodArg([name],[ref],[dsl],[value],[javaCast])

Used to define a factory method argument for the mapped object when using a factory method construction.

name : The name of the method argument. Not used for Java or Webservice construction

dsl : The construction dsl that will be used to construct this setter dependency

value : The constant value you can use instead of a dsl or ref for this setter dependency

javaCast : If using a java object, you can cast the value of this setter dependency

mixins(udfIncludeList)

A UDF template, a list of templates or an array of templates that WireBox should use to mix-in into the target object. It will take all the methods defined in those UDF templates and mixed them into the target object at runtime.

providerMethod(method,mapping)

Will inject a new method or override a method on the target object with a new method that provides objects of the mapping you specify.

virtualInheritance(Mapping)

Create a runtime virtual inheritance from a target object into a target mapping. This approach blends the CFCs together at runtime via mixins and WireBox Funkyness!

extraAttributes(struct)

Allows the ability to store extra metadata about a mapping into WireBox that can later be retrieved via AOP invocations or WireBox events.

Mapping Extra Attributes

You can store a-la-carte attributes in a specific mapping so it can be retrieved at a later time by either an AOP aspect or Events. This is a great way to store custom metadata about an object so it can be read later for some meaningful purpose. Let's say you want to tag a mapping with a custom type that is not so easily determined from the object instance itself. You don't want to do all kinds of introspection in order to know what object you received in an aspect or an event.

This mapping declares that an object has some extra attributes that will be stored in the mapping, such as the location, if it is a custom plugin, if it belongs to a module and a marker that determines if it is a plugin or not. This is then incredibly useful when you have an attached listener to WireBox:

As you can see from this sample, the extra attributes are incredibly essential, as the listener just sends the target object. It would take lots of introspection and metadata inspections in order for me to determine if the incoming object is my system's plugin or not. However, with the extra attributes, it is just a snap!

Component Annotations

The following are all the annotations that are discovered by WireBox on any component declaration that WireBox constructs:

Annotation

Type

Description

autowire

boolean

All objects are marked as autowire=true, so if you want to disable autowiring, you can add this annotation as false. You do NOT need to add this annotation if you want to autowire it, it is redundant if you do.

alias

string

A list of aliased names you can attach to a CFC instance apart from its Component name. This is great when using the mapDirectory() binder function.

eagerInit

none

All objects are lazy loaded unless they are marked with this annotation or marked as eager init in the binder configuration.

threadSafe

none or boolean

Determines the locking construction of the object for its wiring of dependencies. Please see our Object Persistence & Thread Safety Section.

scope

string

A valid WireBox scope or a custom registered scope. Remember that ALL components by default are placed in the NO SCOPE scope. This means they are considered transient objects.

singleton

none

Marks a component as a singleton object.

cachebox

string

Marks a component to be stored in CacheBox. The value of this annotation should be a valid registered CacheBox cache provider. The default cache provider is called default

cache

boolean

Marks a component to be cached in CacheBox in the default provider.

cacheTimeout

numeric

The timeout in minutes when the object is stored in the CacheBox provider

cacheLastAccessTimeout

numeric

The timeout in minutes when the object is stored in the CacheBox provider

mixins

list

A list of UDF templates to mixin into the object

Scope Persistence Annotations

The following annotations can be placed in the component declaration to tell the WireBox injector where to persist the constructed object. If no scope annotations are found on the component or mappings then the object is treated as NO SCOPE or a prototype/transient object; one that gets constructed every time.

Important : When storing objects in volatile scopes like cache, session, request, etc. You must be careful of not injecting them directly into singletons or other volatile objects as you could have memory leaks via a side effect called Scope Widening Injection. We recommend combining them via WireBox Providers to avoid this side effect.

Injection DSL

The injection DSL is a domain specific language that denotes what to inject in the current placeholder: property, argument, or method via the inject annotation. This injection DSL not only can it be used via annotations but also via our mapping dsl whenever a dsl argument can be used. This DSL is constructed by joining words separated by a : colon. The first part of this string is what we will denote as the injection DSL Namespace.

inject="{namespace}:extra:extra:extra"

Property Annotation

Every cfproperty can be annotated with our injection annotations:

@inject : The injection DSL

@scope : The visibility scope to inject the dependency into. By default it injects into variables scope

Important : In full script components, annotating inline arguments is broken in Adobe ColdFusion 9. You will have to annotate them via the alternative annotation syntax in ColdFusion 9 via the javadocs style comments.

Setter Method Annotation

You can also annotate setter methods with the inject annotation to provide injections

WireBox offers a wide gamut of annotation namespaces you can use in your applications and ColdBox applications. However, we took it a step further and allowed you to create your own custom DSL namespaces making your annotations come alive! So let's investigate the shipped namespaces:

ID-Model-Empty Namespace

The default namespace is not specifying one. This namespace is used to retreive either named mappings or full component paths.

DSL

Description

empty

Same as saying id. Get a mapped instance with the same name as defined in the property, argument or setter method.

id

Get a mapped instance with the same name as defined in the property, argument or setter method.

id:{name}

Get a mapped instance by using the second part of the DSL as the mapping name.

id:{name}:{method}

Get the {name} instance object, call the {method} and inject the results

model

Get a mapped instance with the same name as defined in the property, argument or setter method.

model:{name}

Get a mapped instance by using the second part of the DSL as the mapping name.

model:{name}:{method}

Get the {name} instance object, call the {method} and inject the results

// Let's assume we have mapped a few objects called: UserService, SecurityService and RoleService
// Empty inject, use the property name, argument name or setter name
property name="userService" inject;
// Using the name of the mapping as the value of the inject
property name="security" inject="SecurityService";
// Using the full namespace
property name="userService" inject="id:UserService";
property name="userService" inject="model:UserService";
// Simple factory method
property name="roles" inject="id:RoleService:getRoles";

Virtual Inheritance

You can make two CFCs blend together simulating a virtual runtime inheritance with WireBox. WireBox will grab the target CFC and blend into it all of the virtual inheritance CFC's methods and properties. It will then also create a $super reference in the target and a $superinit() reference. This is a great alternative to real inheritance and allow for runtime mixins to occur. You start off my mapping the base or source CFC and then mapping the target CFC and declaring a virtualInheritance to the base or source CFC:

This will grab all methods and properties in the AbstractModel CFC and mix them into the UserService, then create a virtual $super scope which will map to an instantiated instance of the BaseModel object.

Runtime Mixins()

You can use the mixins() binder method or mixins annotation to define that a mapping should be mixed in with one or more set of templates. It will then at runtime inject all the methods in those templates and mix them into the target object as public methods.

This will grab all the methods in the base.cfm and model.cfm templates and inject them into the target mapping as public methods. Awesome right?

The list of templates can include a .cfm or not

Parent Object Definitions

Thanks to Phill Nacelli, you can reuse object definitions in your binder or via annotations. This means that you can declare an object with its dependencies and then create other definitions that use all of this parent object's definitions. This saves tons of time in declarations and provides you with great reusability.

WireBox Event Model

WireBox also sports a very nice event model that can announce several object life cycle events. You can listen to these events and interact with WireBox at runtime very easily, whether you are in standalone mode or within a ColdBox application. Of course, if you are within a ColdBox application, you get the benefit of all the potential of ColdBox Interceptors and if you are in standalone mode, well, you just get the listener and that's it. Each event execution also comes with a structure of name-value pairs called interceptData that can contain objects, variables and all kinds of data that can be useful for listeners to use. This data is sent by the event caller and each event caller decides what this data sent is. Also, remember that WireBox also can be ran with a reference to CacheBox, which also offers lots of internal events that you can tap into. So let's start investigating first the object life cycle events.

WireBox Events

WireBox's offers a wide gamut of life cycle events that are announced at certain points in execution time. Below are the current events announced by the Injector coldbox.system.ioc.Injector.

Event

Data

Description

afterInjectorConfiguration

injector : The calling injector reference

Called right after the injector has been fully configured for operation.

beforeInstanceCreation

mapping : The mapping called to be created

injector : The calling injector reference

Called right before an object mapping is built via our internal object builders or custom scope builders.

afterInstanceInitialized

mapping : The mapping called to be created

target : The object that just go constructed and initialized

injector : The calling injector reference

Called after an object mapping gets constructed and initialized. The mapping has NOT been placed on a scope yet and no DI/AOP has been performed yet.

afterInstanceCreation

mapping : The mapping called to be created

target : The object that just go built, initialized and DI/AOP performed on it

injector : The calling injector reference

Called once the object has been fully created, initialized, stored, and DI/AOP performed on it. It is about to be returned to the caller via its getInstance() method.

beforeInstanceInspection

mapping : The mapping that is about to be processed.

binder : The configuration binder processing the mapping

injector : The calling injector reference

Called whenever an object has been requested and its metadata has not been processed or discovered. In this interception point you can influence the metadata discovery.

afterInstanceInspection

mapping : The mapping that is about to be processed.

binder : The configuration binder processing the mapping

injector : The calling injector reference

Called after an object mapping has been completely processed with its DI metadata discovery. This is your last chance to change or modify the DI data in the mapping before it is cached.

beforeInjectorShutdown

injector : The calling injector reference

Called right before the Injector instance is shutdown.

afterInjectorShutdown

injector : The calling injector reference

Called right after the Injector instance is shutdown.

beforeInstanceAutowire

injector : The calling injector reference

mapping : The instance mapping

target : The target object for wiring

targetID : The unique target object ID used for wiring

Called right after the instance has been created and initialized, but before DI wiring is done.

afterInstanceAutowire

injector : The calling injector reference

mapping : The instance mapping

target : The target object for wiring

targetID : The unique target object ID used for wiring

Called right after the instance has been created, initialized and DI has been completed on it.

Note: Please see our CacheBox documentation to see all of CacheBox's events.

WireBox Listeners

We have already seen in our previous section all the events that are announced by WireBox, but how do we listen? There are two ways to build WireBox listeners because there are two modes of operations, but the core is the same. Listeners are simple CFCs that must create methods that match the same' name of the event they want to listen to. If you are running WireBox within a ColdBox application, listeners are Interceptors and you declare them and register them exactly the same way that you do with normal interceptors. Also, these methods can take up to two parameters depending on your mode of operation (standalone or coldbox). The one main difference between pure Wirebox listeners and ColdBox interceptors are that the configure method for the standalone WireBox is different. Please see samples.

ColdBox Mode Listener

Argument

Type

Execution Mode

Description

event

coldbox.system.web.context.RequestContext

coldbox

The request context of the running request

interceptData

struct

standalone-coldbox

The data structure passed in the event

So let's say that we want to listen on the beforeInjectorShutdown and on the afterInstanceCreation event in our listener.

Please note the configure() method in the standalone listener. This is necessary when you are using Wirebox listeners outside of a ColdBox application. The configure() method receives two parameters:

injector : An instance reference to the calling Injector where this listener will be registered with.

properties : A structure of properties that passes through from the configuration file.

As you can see from the examples above, each Listener component can listen to multiple events. Now you might be asking yourself, in what order are these listeners executed in? Well, they are executed in the order they are declared in either the ColdBox configuration file as interceptors or the WireBox configuration file as listeners.

Important: Order is EXTREMELY important for interceptors/listeners. So please make sure you order them in the declaration file.

Providers

Let's get funky now! We have seen how to inject objects and how to scope objects. However, we need to talk about a cool WireBox feature called object providers. We learned that when you request an object from WireBox it creates it and injects it immediately. However, sometimes we need more control like:

Delay construction of the dependency until some point in time during your controlled execution. Maybe you don't want to construct some dependencies until some feature in your application is enabled.

You need multiple instances of a class. Like a User service producing transient users, or our espresso machine creating espressos.

You need to access scoped objects that might need reconstruction. Maybe you want to check the cache first for existence or a ColdFusion scope in order to avoid scope widening injection.

You have some old legacy funkiness for building stuff that has to remain as its own factory

All of these areas is where WireBox Providers can really save the day. WireBox offers automatically a way to create providers for you by creating generic provider classes (coldbox.system.ioc.Provider) that will be configured to provide the mapping you want, then injected instead of the real object requested. This happens whenever you use the provider DSL injection namespace or annotate methods with a provider annotation. It also gives you an interface (coldbox.system.ioc.IProvider), which is very simple, that you can implement in order to register your own complex providers with WireBox. You would usually do the latter if you have legacy code you need to abstract out, had funky construction processes, etc. Let's start by looking at how registering custom providers work first and then how to use the automatic WireBox providers work.

Custom Providers

If you need to abstract old legacy code or have funky construction processes, we would recommend you build your own provider objects. This means that you will create a component that implements coldbox.system.ioc.IProvider (one get() method) and then you can map it. Once mapped, you can use it anywhere WireBox listens for providers:

The injection DSL ->

property name="" inject="provider:{name or injectionDSL}";

The mapping DSL

map("MyCFC").toProvider('name or injectionDSL')
// or
setter,property,methodArg,initArg(name="",dsl="provider:{name or injectionDSL}");

The CFC you build will need to be mapped so it can be retrieved by name and also so if it needs DI or any other WireBox funkiness, it can get it. So let's look at our FunkyEspressoProvider that we needed to create since we have some old legacy machines that we need to revamp:

Finally we map to the provider using the .toProvider() mapping method in the binder so anytime somebody requests an Espresso we can get it from our funky provider. Please note that I also map the provider because it also has some DI needed.

component extends="coldbox.system.ioc.config.Binder"{
function configure(){
// map the provider first, so it can be constructed and DI performed on it.
map("FunkyEspressoProvider")
.to("model.legacy.FunkyEspressoProvider");
// map espresso's to the old funky provider for construction and retrieval.
map("Espresso")
.toProvider("FunkyEspressoProvider");
}
}

Cool! That's it, anytime you request an Espresso, WireBox will direct its construction to the provider you registered it with.

toProvider() closures

The mapping destination toProvider() can also take a closure that will be executed whenever that mapping is requested. This allows you to add your own custom provider construction code inline without creating a standalone provider object that implements our provider interface. By leveraging closures you can really get funky and more concise in your coding:

Virtual Provider Injection DSL

You can inject automatic object providers by using the provider injection DSL namespace (See above for full reference). This will inject a WireBox provider class (coldbox.system.ioc.Provider) that follows our Provider pattern with one method on it: get() that will provide you with the requested mapped object. The difference between custom providers here is that WireBox will create a virtual provider object for you dynamically at runtime, configure it to retrieve a specific type of mapping and then use that for you. The provider namespace will take everything after it and evaluate it as either a named mapping or a full injection DSL string.

For example, inject="provider:MyService" will inject a provider of MyService objects, so it will look for a MyService ID in the binder. However, you can also get mega funky and do this: inject="provider:logbox:logger:{this}" and WireBox will create a provider of logbox:logger:{this}.

Important: Remember that the value of the provider can be a simple ID or a full injection DSL.

// use the provider DSL namespace on a property
property name="searchCriteria" inject="provider:requestCriteria";
// use the provider DSL namespace on a constructor argument
function init(coolObjectProvider inject="provider:HardToConstructObject"){
variables.coolObjectProvider = arguments.coolObjectProvider;
returnthis;
}
// To use it
searchCriteria.get().getCriteria();
coolObjectProvider.get().executeSomeMethod();

That's it! You basically use the provider:{mapping} injection DSL to tell a property, setter or argument that you want a provider object instead of the real deal. This will allow you to delay construction of such object or avoid the nasty pitfall of scope widening injection.

Virtual Provider Mapping DSL

You can also use our cool mapping DSL to create mappings that refer to provided objects by using the DSL construction type:

You can use the following mapping methods to map to virtual providers by using their dsl arguments:

mapDSL()

initArg(name="",dsl="")

property(name="",dsl="")

setter(name="",dsl="")

methodArg(name="",dsl="")

Virtual Provider Lookup Methods

This is a ColdFusion 9/10 feature only, where you can mark methods in your components with a special provider annotation so they can serve the objects you requested automatically for you. This is an amazing feature as it will take the original method signature and replace the method for you with one that will serve the provided objects for you automatically. How insane is that! You deserve some getting jiggy wit it dancing!

public Espresso function getEspresso() provider="espresso"{}

Wow! That's it! Yep, just create an empty method signature and annotated with provider={mapping} and then WireBox will read these annotated methods and replace them for you at runtime so when you call getEspresso() it actually calls the WireBox injector and requests a new espresso instance and it returns it.

Important: Please note that the visibility of provided methods does not matter to WireBox. It can provide public, private, or packaged visibilities with no problem at all.

Provider onMissingMethod Proxy

Thanks to our friend Brad Wood, we have a feature in our Providers that you can leverage its onMissngMethod() to proxy calls into the provided object itself. So let's say our provided object has a method called sayHello(), then with an injected provider you must do this:

The WireBox provider object (coldbox.system.ioc.Provider) has an onMissingMethod() function that will take all missing method calls and proxy them to the provided object. Now, this is great but be ready to lose on performance if you use this approach. That is the only caveat to this approach, is that you will be impacted by performance, not crazy, but try it.

Scope Widening Injection

An object that is scoped into request, session, server, cachebox or application scopes and if wired into a persisted object will remain around even when this object has expired from the scope. This is called scope-widening injection and is a problem that must be addressed by NOT injecting them into persisted objects directly but by using WireBox's provider approach. This guarantees that the object's scope lifecycle will be maintained and your singleton or other persistent objects will be decoupled from the scope by accessing the target object via its provider.

For example, let's say you have a handler that wires in a user object that is scoped into session scope, but the handler itself is scoped as a singleton:

So when the handler is created and persisted as a singleton, the user object get's created, stored in session and also referenced into the lifecycle of the handler object. So now, if the user expires from session, the handler does not know about it, because all it knows it that a direct reference to that out of context object still remains. So if the user needed things in session to exist, this will now fail. This problem is much how hibernate and detached objects works. Objects are no longer in session, they are detached. This scope widening issue is resolved by NOT injecting the user object directly into the handler but by using a provider.

That's it! My getUser() method will be replaced by WireBox with a proxy provider method that will request from the WireBox injector the user mapping instance.

Object Persistence & Thread Safety

While the injector can help in many ways to secure the creation of your objects, it is ultimately up to you to create code that is both thread safe and tested. It is always a great idea to design your objects without the injector in mind for threading and concurrency. DI is not a silver bullet, but a tool to relieve object creation and not to relieve the burden of good object design. Thread safety is much more complex and can be compromised when using persistent scopes like singleton, session, server, application and cache box, as more than one thread will be trying to access your code and dependencies. The only guarantee the injector can provide is the constructor and constructor dependency creation to be completely locked. The following object is to be guaranteed to be locked when created and wired with dependencies:

Why is this object flawed? It is flawed because the majority of DI engines, including WireBox, will lock for constructing the object and its constructor arguments. However, once it is constructed, it will store the object in the persistence scope of choice in order to satisfy the potential of circular dependencies in the object graph. After it is placed in the storage, the DI engines will wire up setter and property mixin injections and WireBox's onDiComplete() method. With this normal approach, the wiring of dependencies and onDiComplete() have the potential of mixups due to concurrency. This is a normal side-effect and risk that developers take due that Java makes no guarantees that any thread other than the one that set its dependencies will see the dependencies. The memory between threads is not final or immutable so properties can enter an altered state.

"The subtle reason has to do with the way Java Virtual Machines (JVM) are designed to manage threads. Threads may keep local, cached copies of non-volatile fields that can quickly get out of sync with one another unless they are synchronized correctly." From Dependency Injection by Dhanji R. Prasanna

Note: This side effect of concurrency will only occur on objects that are singletons or persisted in scopes like session, server, application, server or cachebox. It does not affect transient or request scoped objects.

WireBox, can help you lock and provide thread safety to setter and property injections by providing you with the ThreadSafe annotation or our binder threadSafe() tagging method. So if we wanted to make the last example thread safe for property and setter wiring then we would do the following:

Note: All objects are marked as non thread safe for dependency wiring by default in order to allow for circular dependencies. Please note that if you mark an object as threadSafe, then it will not be able to support circular dependencies unless it uses WireBox providers. ( See Providers Section )

Our threadSafe annotation and binder tagging property will allow for these objects to be completely locked and synchronized for object creation, wiring and onDiComplete(). However, circular dependencies will now fail as persistence cannot be guaranteed for the setter or property dependencies. However, since WireBox is so awesome, you can still use circular dependencies by wiring instead our object providers. (Please see providers section). In conclusion, constructing and designing a CFC that is thread safe is often a very arduous process. It is also very difficult to test and recreate threading issues in your objects and applications. So don't feel bad, as even the best of us can get into some nasty wormholes when dealing with concurrency and thread safety. However, always try to design for as much concurrency as possible and test test test!

Custom DSL Builder

WireBox allows you to create your own DSL object builders and then register them via your configuration binder. This allows you to create a namespace or override an internal namespace with your own object builder. By now we have seen our injection DSL and noticed that we have internal namespaces. With this feature we can alter it or create new ones so our annotations and injection DSLs can be customized to satisfaction. This is easily done in the following process

The main method here to notice is the process() method. This method receives the injection dsl annotation value and it will be up to the builder to parse it and decide what to do with it. If this method returns null then WireBox will log it for you at that specific injection dependency resolution. However, we also encourage you to use best practices and log from your builders also.

Registering a custom DSL builder

If you refer back to the configuration section you can see the customDSL structure or mapDSL() method that you can use for registering custom DSL namespaces.

As you can see from the sample, creating your own DSL builder is fairly easy. The benefits of a custom DSL builder is that you can very easily create and extend the injection DSL language to your own benefit and if you are funky enough, override the behavior of the internal DSL Namespaces.

Custom Scopes

WireBox allows you to create your own object persistence scopes so you can have full control on their lifecycle. This is easily done in the following process:

Create a CFC that implements coldbox.system.ioc.scopes.IScope

Register your custom scope in your configuration binder

You can create your own persistence scope or if you are getting funky, override the internal persistence scopes with your own logic.

Scoping Process

The scoping process must be done by using some of the referenced injector's methods:

buildInstance(mapping, initArguments)

autowire()

These methods must be called sequentially in order to avoid circular reference locks. The first method buildInstance is used to construct and initialize an object instance. The autowire method is used then to process DI and AOP on the targeted object. Let's look at my Ortus Scope:

WireBox IInjector Interface

We also provide an interface to create objects that adhere to our injector interface: coldbox.system.ioc.IInjector. Then these objects can be used as parent injectors, great for legacy factories or creating hierarchies according to your specs. All you have to do is implement the following interface:

Criteria Builder : Tap into the power of Hibernate Criteria Queries with our Criteria Builder

Detached Criteria Builder : With the new Detached Criteria Builder, you can expand the power and flexibility of your criteria queries with support for criteria and projection subqueries, all while using the same intuitive patterns of Criteria Builder

ORM Entity Injection : Use WireBox for applying dependency injection & AOP to ORM entities. Also use it as a way to proxy hibernate listeners

WireBox Object Populator

WireBox also comes packaged with our handy ColdBox object populator that has been so successful in our ColdBox applications. The object populator object can populate objects with data from XML, JSON, WDDX, structures, queries and much more. So we highly encourage you to check it out as it will really help out in your applications. The way to retrieve it is to use the getObjectPopulator() method on the injector and then call one of our populate methods you can see below. Please check out the CFC docs API for the latest and greatest.

If set to true, the setter method will be called even if it does not exist in the bean

include

string

No

A list of keys to include in the population

exclude

string

No

A list of keys to exclude in the population

ignoreEmpty

boolean

No

false

Ignore empty values on populations, great for ORM population

nullEmptyInclude

string

No

A list of keys to NULL when empty

nullEmptyExclude

string

No

A list of keys to NOT NULL when empty

composeRelationships

boolean

No

false

Automatically attempt to compose relationships from memento

populateFromStruct

Populate a bean from a structure

Returns

This function returns any

Arguments

Key

Type

Required

Default

Description

target

any

Yes

---

The target to populate

memento

struct

Yes

---

The structure to populate the object with.

scope

string

No

---

Use scope injection instead of setters population.

trustedSetter

boolean

No

false

If set to true, the setter method will be called even if it does not exist in the bean

include

string

No

A list of keys to include in the population

exclude

string

No

A list of keys to exclude in the population

ignoreEmpty

boolean

No

false

Ignore empty values on populations, great for ORM population

nullEmptyInclude

string

No

A list of keys to NULL when empty

nullEmptyExclude

string

No

A list of keys to NOT NULL when empty

composeRelationships

boolean

No

false

Automatically attempt to compose relationships from memento

populateFromQueryWithPrefix

Populates an Object using only specific columns from a query. Useful for performing a query with joins that needs to populate multiple objects.

Returns

This function returns any

Arguments

Key

Type

Required

Default

Description

target

any

Yes

---

This can be an instantiated bean object or a bean instantiation path as a string. If you pass an instantiation path and the bean has an 'init' method. It will be executed. This method follows the bean contract (set{property_name}). Example: setUsername(), setfname()